Various objects to be conveyed, including mineral resources such as iron ore and limestone, are conveyed by a conveyor belt. When the objects to be conveyed are fed onto the upper cover rubber of the conveyor belt, the upper cover rubber is subjected to impact, and when the surfaces of the objects to be conveyed are sharp, the surface of the upper cover rubber may sustain cut damage in some cases.
Various methods for evaluating the impact resistance of a conveyor belt have been proposed in the past (see for example Japan Patent Publication Nos. 2010-216852, 2011-257187 and 2012-189533). Ordinarily, the impact resistance of rubber is evaluated by understanding the damage condition of a test sample into which an impact application member such as a weight has collided.
The impact resistance of the upper cover rubber differs depending on the rubber characteristics, usage environment, etc. Therefore, the appropriate rubber for the upper cover rubber needs to be selected with consideration of the impact resistance during actual use of the conveyor belt.